Maillage dynamique du scaphoïde carpien : une aide au vissage percutané

Abstract

Despite the use of cannulated compression screws, it is still difficult to screw non-displaced fractures of the scaphoid percutaneously. That is due in particular to the difficulty in assessing the correct position for the guide pin from the 2D fluoroscopic images. This work is designed to enable 3D visualisation of the scaphoid during surgical operations by using the technique of dynamic meshing and having the image appearing on a computer screen rather than as a mental image. In this context, the MEFP3C software includes applications for converting a generic scaphoid into a virtual scaphoid, based on the fluoroscopic 2D images of a given scaphoid. These applications include a module for acquiring a cloud of points, a modeller, a dynamic meshing system, an animation module, a texture module and a multi-resolution meshing system. The result of this process, the virtual scaphoid, in spite of the imperfections, enables images to be obtained comparable with those from tomodensitometric reconstruction of the same scaphoid specimen. The virtual scaphoid can be moved over the computer screen in the three spatial planes in translation, rotation and scaling. In conclusion, we think that dynamic meshing is a powerful, simple and ergonomic method of viewing a scaphoid in 3D, which could, in future, be routinely integrated into the fluroroscopic monitor.